Plastic waste represents one of the most significant environmental challenges facing the world today, with microplastics emerging as a focal point for researchers over the past few decades. Pollution from microplastics is accumulating in aquatic ecosystems at an unprecedented scale, serving as new surfaces for biofilm formation and gene exchange. Recent studies have highlighted the negative impacts of microplastics on marine life. The effects of microplastics on sea creatures primarily occur through the direct ingestion of plastic particles, leading to internal damage. Additionally, these pollutants adversely affect the distribution of certain marine species that utilize these materials as sites for laying eggs. Consequently, the presence of microplastics in seawater-especially given the high consumption of seafood (fish and shellfish) in some countries-raises concerns regarding their potential impact on human health. Many researchers emphasize that one of the most critical effects of microplastics in marine environments is their ability to absorb chemical pollutants. Beyond merely transporting these contaminants, microplastics also enhance the environmental stability of these substances. Microplastics provide an extensive and suitable substrate for microbial accumulation in aquatic ecosystems. The formation of microplastic-microorganism complexes, such as biofilms, facilitates the degradation of organic matter and horizontal gene transfer. In this context, microplastics influence the structure and function of microbial communities, revealing both physical and chemical effects that pose challenges for microbiology, ecology, and ecotoxicology. The dispersion of microplastics is diverse, encompassing associated microorganisms and genetic elements, including antibiotic resistance genes, pathogenicity islands, and metabolic pathways. Functional changes within aquatic microbiomes can alter carbon metabolism and food webs, leading to unknown consequences for both organisms and human microbiomes-and, consequently, human health. The spread of antibiotic resistance through microplastics poses a significant risk for the evolution of aquatic bacteria and represents an often-overlooked threat to human health. Studies indicate that horizontal gene transfer in this habitat can significantly impact the ecology of aquatic microbial communities on a global scale. Therefore, comprehensive research on microplastics and nanoplastics and their effects within the food chain is essential. This article aims to review various studies on this pollutant and highlight some of its effects in marine environments.

Methyl Tert-Butyl Ether (MTBE) is one of the ether oxygenates which its use has been increased within the last twenty years. This compound is produced from isobutylene and methanol reaction that is used as octane index enhancer and also increases dissolved oxygen in gasoline and decreases carbon monoxide emission in four phased motors because of better combustion of gasoline. High solubility in water (52 g/L), high vapor pressure (0.54 kg/cm3), low absorption to organic carbon of soil and presence of MTBE in the list of potentially-carcinogens of U.S EPA has made its use of great concern. The culture media used in this study was Mineral Salt Medium (MSM). The study lasted for 236 days and in three different concentrations of MTBE of 200, 5 and 0.8 mg/L. A control sample was also used to compare the results.  This research studied the isolation methods of microbial consortium in the MTBE polluted soils in Tehran and Abadan petroleum refinery besides MTBE degradation. The results showed the capability of bacteria in consuming MTBE as carbon source. Final microbial isolation was performed with several microbial passages as well as keeping consortium in a certain amount of MTBE as the carbon source.

Today, many different methods are applied for the correct use of foods and to prevent their deterioration. Ensuring healthy conditions for people in food consumption and consumption of healthy foods is very important for human welfare. In this study, food spoilage, the factors that cause food spoilage, its effects on a global basis, food transport systems (cold chain) and measures that prevent or delay food spoilage are discussed.

Introduction: Chemical antibacterial agents are increasingly being used in prophylactic therapeutic regimes for oral and plaque-related diseases. As the microorganism can be resistant to drugs so, there is a need for alternative antibacterial approaches.Bacteria can be sensitized to killing by light from low-power laser with chemical photosensitizing agents such as TBO. The aim of this study was to investigate the bacterial effect of Ga-As laser irradiation on oral microorganism.Methods: The microorganisms evaluated in this in vitro study were: S.mutans, Group A Beta Hemolytic streptococci, Neisseria, Bacteroides melaninogenicus.Diphteroides, Lactobacilli, Fusobacterium fusiformis, S.aureus, S.epidermis & candida albicans. The bactericidal effect was determined by the enumeration of viable bacterial colonies. Time of irradiation was 20 mibns and frequency 3000 Hz with power 5 watt. Toluidine Blue is selected as a photosentisizer.Results: Ga-As laser irradiation with energy density 1.8j/cm2 resulted in 31.3% mean reduction in CFU number of S.mutans, 30.2% in Diphtheroid, 36.7% in S.epiedermis, 19.2% in Neisseria, 37% in B.melaninogenicus, 32% in Fusobacterium and 44.9% in candida albicans.Conclusion: Ga-As low power laser can be used in preventive dentistry or in treatment of oral lesions.

Biodegradation of styrene by an aerobic microorganism (namely, Rhodococcus erythropolis PTCC 1767) as well as the effects of bacterial cultures non-adapated and adapted to 90 mg/l styrene were investigated. In both cases, an initial biomass concentration of 0.31 mg/l and styrene concentrations of 10, 20, 30, 50, 70, 90, and 150 mg/ l were used and the tests were carried out at 32oC and at pH 7. The results showed that the unadapted bacterial cultures were capable of biodegrading 10 mg/l in 15 h; however, removal efficiency was observed to decrease with increasing initial styrene concentration such that at a concentration of 150 mg/l, only 17% of the biomass was degraded over 48 h. On the other hand, the adapted microorganisms were capable of completly degrading Styrene at various initial concentrations of 10 to 150 mg/l over 2.7F45 h. The kinetics of styrene biodegradation by R. erythropolis PTCC 1767 was also studied. The styrene bioremoval data fitted to the Monod model and to five inhibition kinetic models (namely, Haldane, Webb, Yano, Aiba, and Teissier-type). Among these models, the Haldene one was found to fit satisfactorily the kinetic data (R2>0.99, SSE=0.008) with the following Haldane model parameters: qm=4.235 mg/g dry cell h; Ks= 7.594 mg/l; and Ki=34.58 mg/l.

Background: The objective of this study was to develop a consortium of effective microorganisms to hasten the composting process and to reduce the composting period.Results: An efficient microorganism (EM) consortium was developed using Candida tropicalis (Y6), Phanerochaete chrysosporium (VV18), Streptomyces globisporous (C3), Lactobacillus sp. and enriched photosynthetic bacterial inoculum for rapid composting of paddy straw. Paddy straw was amended with poultry droppings to narrow down its C: N ratio for faster degradation. Composting was carried out in open pits with EM consortium and compared with compost inoculant (CI) consisting of Aspergillus nidulans (ITCC 2011), Tricho derma viride (ITCC 2211), Phanerochaete chrysosporium (NCIM1073) and A. awamori (F-18). Changes in biochemical and physiochemical parameters like C: N ratio, pH, EC and humus were studied over a period of 60 days to test compost maturity and stability along with microbial and extracellular hydrolytic enzyme activities. Paddy straw amended with EM and CI hasten the composting process by bringing C: N ratio down to 15: 1 and achieving a total humus content of 4.82% within 60 days. High activity of hydrolytic enzyme carboxymethyl cellulase (CMCase) (0.43 IU/g) andmicrobial activity in terms of dehydrogenase (158.64 mg TPF/g/day) was observed in this treatment. The activity of xylanase was positively correlated (r=0.987) with alkali-soluble carbon.Conclusion: This study illustrates the importance of microbial bioaugmentation to hasten the composting process of paddy straw to produce quality compost.